TRANSACTIONS OF WAGNER 

 1362 



TERTIARY FAUNA OF FLORIDA 



Shell like Miltha, but with the hinge-teeth wholly obsolete and the valves 

 often less solid and more convex. 



Recent species occur at Panama and in the Gulf of Mexico. The fossils 

 comprise some of the largest of the Lucinacea. 



Subgenus Lucinoma Dall, 1901. Type Lucina filosa Stimpson. 



Shell usually large, lentiform, white with a conspicuous periostracum, con- 

 centrically lamellose or striated; the cardinal teeth developed, the inner pair 

 usually bifid, the laterals obsolete or absent ; the inner margins entire. 



This is a well-marked group with a wide extension in time and geographi- 

 cally, preferably inhabiting cold water and frequently great depths. 



Subgenus Callucina Dall, 1901. Type Lucina radians Conrad. 



Shell orbicular, dosinoid, concentrically filose and sometimes with feeble 

 radial sculpture ; the dorsal areas obsolete ; the lunule small, comprised chiefly 

 in one valve and fitting when closed into a recess in the other valve ; hinge with 

 one cardinal in each valve, the other teeth feeble or absent ; inner margins 

 crenulate. 



Section Epilucina Dall, 1901. Type Lucina calif 'arnica Conrad. 

 Shell veneriform, convex, all the hinge-teeth developed, inner margins en- 

 tire ; otherwise like Callucina. 



Subgenus Parvilucina Dall, 1901. 



Shell small, plump, often inequilateral ; sculpture more or less reticulate 

 but not muricate ; teeth small, but usually all present. 



Section Parvilucina s. s. Type Lucina tenuisculpta Carpenter. 

 Dorsal areas obscure or obsolete, sculpture feeble. 



Section Bellucina Dall, 1901. Type Lucina pisum Reeve (Aug.) 1850, 

 not of Philippi, April, 1850, nor of Sowerby, 1837, nor Orbigny, 

 1841) = Parvilucina eucosmia Dall, 1901. 

 Dorsal areas and sculpture strong. 



Of those early species, which, though usually having the cardinal teeth 

 persistent, may perhaps best be referred to the typical section of this genus, 

 there are but few in our Tertiaries, of which P. Turneri Stanton, 1897,* from 

 the Tejon of California; P. fortidentalis Harris, 1896,! from the Midway hori- 

 zon of Georgia and Alabama, and P. papyraceus Lea, 1833, \ from the 



* Seventeenth Ann. Rep. U. S. Geol. Survey, part i., p. 1042, pi. Ixvi., figs. 6, 7. 

 t Bull. Am. Pal., iv., p. 69, pi. vi., figs, n, iia. % Contr. Geol., p. 58. 



